The present invention relates generally to an automatic focusing and exposing mechanism for photographic apparatuses, and more particularly to an improved mechanism for instantly completing both focusing and exposing operations when photographing fast moving objects; this mechanism also improves the operation sequence of focusing and exposing.
Prior art which teaches automatic focusing and exposing is as shown in FIGS. 1 and 2. According to the operation sequence of the prior art, a motor drives a range ring 1 to rotate in a counter-clockwise direction to initiate the focusing operation, a locking member 11 locks the range ring 1 so that it cannot move freely. When the locking member 11 releases the range ring 1, the motor starts reverse rotation, driving the range ring 1 to rotate in a clockwise direction and to urge against the shutter lever 12 for exposure. The motor then drives the range ring 1 to rotate counter-clockwisely to return to its original position.
The above-described prior art has to utilize the range ring 1 to rotate first counter-clockwisely so as to focus, and then clockwisely so as to actuate the shutter mechanism. After that, the range ring 1 has to rotate counter-clockwisely again to return to its original position. As can be seen, the whole process from focusing to exposure is quite long, and hence the cycle for completing both operations of focusing and exposing is very long. There is another kind of prior art which improves upon the drawbacks in the above-described known art. The Konica camera is herein taken as a typical example. The Konica camera uses two motors as power sources, one for focusing, the other for actuating the shutter; but this configuration is complex and costly. As regards the control of the motors, it requires precise control and is therefore not very satisfactory.